Preferred order of One Time Passcode (OTP) delivery

This setting only affects Rules which contain SMS/Email as a Second Factor.

OPT length

Set the character length of One-Time Passcodes. The default value is 8.

OPT lifetime

This setting dictates how long a generated One-Time Passcode will be accepted. If an authentication attempt is made using an OTP that is older than this value (in seconds), the authentication attempt will fail.